钢筋混凝土框架结构加层、改造及抗震加固

Stories Adding,Renovation and Strengthening of Existing Concrete Frame Structures

按《建筑抗震设计规范》(GBJ11-89)设计的框架结构,如果沿用原框架体系进行加层改造,其抗震性能很难满足《建筑抗震设计规范》(GB50011-2001)规定的弹性层间位移角限值,且加层、抽柱还会造成框架柱轴压比超限,多层框架柱底部计算配筋大于原施工图配筋(实际配筋),以及抗扭刚度变弱,地震扭转效应增大等问题,而改变原框架体系,采用框架剪力墙结构进行加层、抽柱加固能很好地解决以上问题。但应注意到,新加剪力墙基础、墙体与原框架基础、梁、柱的连接,是保证新加剪力墙与原框架整体协同抗震工作的关键。

During the course of stories adding and strengthening for those old buildings, those existing concrete frame structures designed by Code for seismic design of building (GBJ11 - 89) could not meet the rule of allowable value of drift angle of earthquake resistant structure mentioned in Code for seismic design of buildings ( GB50011 - 2001) , if the old concrete frame system is used to add stories, furthermore, stories adding and removing columns shall arouse some problems, such as excessive axial compression ratios of reinforced concrete frame columns, larger calculation reinforcement of the steel - concrete frame columns in the buildings with lower stories frame than the original working drawings, i. e. actual reinforcement, failing in torsional stiffness of member, augmenting in seismic torsional vibration. Above these problems will be readily solved by changing old reinforced concrete frame system into frame shear wall system. But it should be noticed that the sticking point of new adding shear wall with the old structure is the key ensuring collaboration of new adding shear wall with the old structure.